I'm currently rounding the corner to finish a TV restoration. I have replaced all of the electrolytics and many of the paper caps. I also tested most of the tubes and have replaced the ones that were obviously bad. I'm very close on the picture but am looking for a little guidance on what I should try next.

Here's one picture of the tv with a digital antenna signal with a ghost image:

and here's one with about as close as I can get the picture. Just a little more turning radius on the vertical adjustment and I'd be there:

From what I can see it looks like you have something going on with the horizontal.Does this set use a horizontal AFC diode? If so I would check there. Bad Horiz osc tube can cause things like this too.

Horz osc is way off freq.1) try horz osc tube.2) be sure you used the right value caps in the horz osc.3) dont remember on these but newer Zeniths all used a coil for hoz hold.It has a stop on it that is a sleeve you pull out to rotate further. Be sure the slug is about in themiddle of the coil. If you keep turning it one way you will get one normal pix. The opposite way will give you more pictures side by side..........

Here's one picture of the tv with a digital antenna signal with a ghost image:

Any thoughts appreciated!

craig.

I'm not sure what you mean by "digital antenna with a ghost image". Are you using a digital converter in the first picture? I don't see how you would get a ghost image that way. Maybe you mean you are getting a double image, maybe a sync problem.Double check the capacitor values in the horizontal and vertical sections.

This is a Horizontal problem, if the coil slug has to be adjusted all the way in or out to get it that close but it still won't quite lock in then you may have the wrong value cap across the Horizontal Oscillator coil or a drifted resistor in that circuit.

My 2 cents....that horizontal coil sings at that particular resonant frequency, with a cap across it. That piece of it looks fine. There are going to be one or two feedback loops comparing frequencies, any difference will show as a correction to bring the oscillator on frequency. The comparison is the pair of face-to-face diodes. Your problem is an adjustment of the coil or some imbalance in the wiring around the diodes. Craig

If those 60+ year-old paper caps aren't leaky now, they will be soon. You don't want to "finish" a restoration and then keep hauling the TV back onto the workbench over and over, as the remaining caps give up the ghost.

If you still have the same symptom at that point, then I'd take Eric's advice and look closely at resistors in the horizontal circuits, as well as mica caps in those circuits. Although mica caps are generally more reliable than paper, they fail fairly often in sweep circuits, where they take more abuse than in other sections.

Thank you to everyone for the great advice. After reviewing all the suggestions and looking at the circuits, I found a more than order of magnitude wrong capacitor that I installed. After correcting that, I then went through the low resistance (<1kOhms) resistors and found a few that were more than 30% off. One was double the markings.

Once I made all these changes and replaced a tube, I'm in very good shape:

Now I can watch all my favorite sports while working on projects in my workshop. Thank you everyone for helping! If you notice anything that can be improved in the picture, please let me know. I feel that the image is slightly off-center and will take a look at the bullseye setting, assuming no one tells me to stay away from that!

I feel that the image is slightly off-center and will take a look at the bullseye setting, assuming no one tells me to stay away from that!

Your screen geometry looks pretty decent at a glance, but if you want to tweak it, look in your manual for adjusters with names like vertical height, horizontal width, vertical and horizontal centering, vertical linearity, horizontal linearity. Not every TV has all those adjusters, so work with what you've got. You can't harm your TV by messing a little with these adjustments, unless you pound an adjuster with a sledgehammer.

Note that these adjustments are somewhat interactive:

-- height and vertical linearity-- width and horizontal linearity

For example, turning the vertical linearity adjuster may somewhat affect the height, and vice versa. If you go back and forth between the two, making small changes, you'll soon see how they interact.

Linearity defines whether the picture is stretched (vertically or horizontally) in one half of the screen versus the other half. The following screen shows a TV with pretty good linearity:

The squares in the top row are about the same height as those in the bottom row, showing good vertical linearity. The squares in the far left column are about the same width as those in the far right column (good horizontal linearity).

The circle in the pattern also helps you judge linearity. The next photo shows a different TV with poor vertical linearity. The top part of the screen is stretched vertically, making the circle somewhat egg-shaped:

If you don't have a dedicated TV pattern generator, you can go to this website and make a DVD with various TV test patterns:

Now I can watch all my favorite sports while working on projects in my workshop. Thank you everyone for helping! If you notice anything that can be improved in the picture, please let me know. I feel that the image is slightly off-center and will take a look at the bullseye setting, assuming no one tells me to stay away from that!

cheers.

craig.

IIRC the Zenith "bullseye" was a tuner setting (to adjust channel fine tuning)....It will have NO effect on scan centering/geometry.

If the bullseye gizmo is a fine tuner, there's no harm in trying it out. No expertise required -- just let your eyes and ears tell you when the picture and audio are at their best (from a tuning standpoint).

Thanks for the tips on fine tuning, everyone. This is very helpful and I see a very small bit of deformation at the top so I'll play around with this. That image for visually seeing the stretching is great. Now I have to find a DVD player. Since I have a chromecast attached, I suppose that I could just stream a still picture from youtube: https://youtu.be/po_hBMtTaDg?t=2m5s

Well, looks like I'm about done. The channel changer box (not sure of the name) had a few resistors that were off quite a bit and once I changed those and chromecasted the youtube video, I could see straight lines and round circles, as expected:

I've hit to limit on how far to the right that I can move the picture, which is why the circles on the right edge are just a bit bigger than the ones on the left edge. And the top has a very narrow sliver of space that isn't filled. Neither of these issues bothers me, but if someone has seen this and knows what the issue might be, I'm all ears.

Now that I have the tv finished, I can crank up the Rock Band in the privacy of my man cave:

Thank you to everyone for all the hints and suggestions over the last few months! Very satisfying and everyone I show it to is amazed at the quality of the picture!